Location-based services have been applied in varied scenarios, for which accurate positioning is a key issue. Satellite based positioning services, such as Global Positioning System (GPS) and Galileo system, are capable of provide accurate positions of target objects in outdoor environment. However, as known, such satellite based solutions are not applicable for indoor positioning. As an example, GPS loses significant power when passing through construction materials, and suffers from multi-path propagation effects that make it unsuitable for indoor environment.
It has been proposed to leverage existing WiFi or Bluetooth wireless communication infrastructure to provide indoor positioning services. Although WiFi based positioning solutions may be deployed and used with relatively low costs, they only provide accuracy of up to few meters suffering from wireless channel dynamics, fading, interference and environmental noises. For example, complex indoor environments cause radio waves to propagate in dynamic and unpredictable ways, limiting the accuracy of such positioning systems. As a result, positioning solutions based on wireless communications cannot meet requirements of many applications.